iOS (Jailbreak): If you don't want Safari saving your browsing history, you have to drop into the Settings menu and enable Private Browsing. This can be a bit cumbersome when you're just looking for a quick switch. Privata is a jailbreak tweak that adds a private browsing toggle right in Safari itself.

With Privata installed, tap the action button at the bottom of Safari (in the middle), and then tap "Toggle Private Browsing." When you're in private browsing mode, the screen changes to a darker color, and everything you do from then on out won't be saved or recorded. A number of alternative browsers have this built-in, but if you're a fan of Safari and want a quick toggle for privacy, Privata does the trick. Privata is a free download in the ModMyi repository.